1. Field of the Invention
The present invention relates to a solid-state image sensor and a camera.
2. Description of the Related Art
A solid-state image sensor used in a digital video camera, a digital still camera, or the like is required to undergo constant improvement in sensitivity. Japanese Patent Laid-Open No. 63-14466 discloses a technique for decreasing loss of incident light due to reflection from the surface of a photoelectric conversion element by using an antireflection film on the surface of the photoelectric conversion element. Japanese Patent Laid-Open No. 2005-142510 discloses a technique for setting the thicknesses of antireflection films provided under color filters for red, green, and blue lights so that the reflectivity is minimized in the respective wavelength region.
The spectral characteristics of the whole solid-state image sensor are determined by multiplying the spectral transmittance of a color filter by that of an antireflection film. As disclosed in Japanese Patent Laid-Open No. 2005-142510, if the thicknesses of the antireflection films for red, green, and blue lights are simply set so that the reflectivity is minimized in the respective wavelength region, the color separation characteristics may degrade.